Slack adjuster



sept, 27, 1932. R B. CAMP 1,879,075

SLACK ADJUSTER Filed Nov. 28, 1930 3 Sheets-Sheet 1 Sept. 27,- 1932. Y P. B. CAMP L8775 SLACK ADJUSTER Filed Nov. 28, 1930 3 Sheets-Sheet 2 @mjy Sept. 27, 1932. P. B. cAMP SLACK ADJUSTER y Filed Nov. 28, 1930 3 Sheets-Sheet '3 STATES PA're'r trams :BERCY CAMP, 0F MIAYWOOD, ILLINOIS, ASSIGNOR T0 UNIVERSAL DRAFT GEAR TACHMENT CO., A CORPORATION OF ILLINOIS SLACK ADJUSTER Application filed November 28, 1930. Serial No.498,653.

rlhis invention relates to railway brakes and more particularly to slack adjusters therefor. 3

One of the objects of the invention is the provision of new and improved means for automatically taking up the slack in the brake operating mechanism for railway trains..v

Another object of the invention is the provision of new and improved means for lock- 10 ing the parts in brake operating positions when the device is notfunctioning as a slack adjuster. i j

A further object of the invention is the provision of new and improved slack adjusting devices that may be mounted on and movable with portions of the brake operating mechanism, and that is so constructed that the use of the device will not in any way interfere with the normal operation of the brake operating mechanism.

A still further object of the .invention is the provision of a slack adjuster that is simple in construction, inexpensive to manufacture, automatic in action, ehcient in operaf tion, and that is not likely to become broken or get out of order. L'

Other and further objects'and advantages of the invention will appear from the following description taken in connection with the accompanying drawings, in which Fig. 1 is a plan view of the slack adjusting mechanism; Fig. 2 is a section on line 2-i2 of Fig. 1;

j Fig. 3 is a side elevation of the device, with parts in section and parts broken away, showing the adjusting mechanismin position for taking up the slack;

Fig.4 is a view similar to Fig. 3, but showing the device at the completion of its slack adjusting movement;

Fig. 5 is a section on line 5-5 of Fig. 4; j

Fig. 6 is a side elevation of the device, the view being taken from the opposite side from that shown in Fig. 4; j j

. Fig. 7 is a section on line 7 7 of Fig. 4;

Fig. 8 is a section on line'8-8 of Fig. 4;

Fig. 9 is a diagrammatic view of the brake operating mechanismas applied to the trucks of a railway car;

sa Fig. 1() is a perspective view ofthe attaching member or housing withparts brokenV Fig. 11 is a perspective view of the adjusting mechanism; and l Fig. 12 is a perspective viewvof the holding or retaining member. Referring now to Fig. 9 of the drawing, the reference characters 410 indicate railway trucks having the wheelsll, and the brakes therefor comprising the live and dead brake levers 12-and 13 respectively, brake shoes 14 and 15 operated by said levers, connecting bar 16,.brake rod 17 ,the live anddead` cylinder levers 418 and 19, the cylinder lever connection 21 and the brake cylinder22, as usual in such constructions. Y f

In the construction and operation of railway bra-kes, the parts are so constructed and arranged that the operating piston of the air cylinder will have a Vpredetermined travel, usually about 8".V As the shoes become worn, this distance will increase unless provision be made for taking up the slack,and since the levers are so arranged as `to transmit their maximum power at the limit of travelk of the piston when the shoes are first applied, it follows that the efficiency of the brake is greatly reduced when the shoes ybecome worn, unless means'are provided for maintaining the parts in apredeterminedrelation j The present invention seeks to provide means for automatically taking up the slack during the operation ofthe brakes, for. compensating for the `wear of the brake shoes. It' is also. desirable that this mechanism be so constructed that it may be attached to the moving parts of the brake operating mechan-, ism and will not interfere with thevnormal operation of this mechanism.

In the formV of construction shown, Which is by way of example only, the slack adjusterv is `designated generally by the reference char--V acter 23 and is shown as being applied to bothy the live and dead cylinder levers 18 and 19,v see Fig. 9. It is understood, however, that it may be applied to other parts of the moving mechanism if so desired. l Y

The adjustercomprises an attaching member or anchor member 24 which may be inV the form of a housing having theupper wall we' i 25, side walls 26 and 27 respectively, and a ledge 28 on its lower portion. The side wall V27 is provided with a slot 29 through which the attac-hing lever may extend as will presf ently appear. rEhe housing 24 is provided the housing. As shown, the wall 25 is provided with integral rack teeth Vat each side thereof. A holding orretaining member designated generally by the reference character 34 is. slidably mounted Within the housing and is provided with one or more teeth 35 for engaging the teeth 33 of said housing. Preferably a plurality of teeth 35 are employed,

a arranged in sets at opposite sides of an opening 36 extending through said retaining member. The two sets of teeth 35 are adapted to engage the two sets-ofV teeth 33 on the wall 25 as shown in Figs. 4 and 5 ofthe drawings. The holding member 34 is provided with an one end of the cylinder lever 18 which also extends through the slot 29 in the attaching or holding member 24. The rear portion of the slot extends downwardly and outwardly for receiving the pivot pin of the adjusting device as will presently appear. A pin 38, see Fig. 2, extends through the aligned openings 36 in the holding member 34 for pivotally connecting the cylinder lever 18 to said holds member 34. Suitable means are provided for advancing the housing 24 relative to the holding member step by step for compensating for the wear in the brake shoes, that is, for taking up the slack inthe brake operating mechanism,

caused by the wearing of the brake shoes.

As shown, adjusting mechanism designat-v ed generally by the reference character 39 is employed for this purpose. This mechanism comprises a lever 41 having a detent 42 slid ably mounted in one end thereof and its opposite end provided with a spring seat 43. The detent 42 is normally held in extended posi-V tion by a spring 44 housed within said detent and the upper end of said lever. The lever is pivotally mounted in any suitable mannerV in the depending portion of the slot 37 of the holding member 34. LAs shown, the member 34 is bifurcated at what vfor convenience of description will be termed yits rear end, thereby providing a slot 45 through which the upper end of the lever 41 is adapted to extend. By `means of this arrangement the adjusting mechanism will function without undue friction since the friction due to its operationwill be equalized on the two sides of the adjusting lever.

The lever 41 is provided with a trunnion or pivot pin 46 for engaging the rear depending portion of the slot 37. 'In the form of construction shown, which is by way of example only, the pin or trunnion 46 is separate from the lever 41. It is provided with an angular portion 40 which engages a corresponding angular opening in said lever. The en d of the pin is provided with a collar 50, see Fig. 11, for constituting a journal of thel same diameter as the inner portion' of the trunnion 46. l

The retaining member 34 is provided with a spring seat 47 on its lower portion which is arranged'opposite thespring seat 43 when the parts are assembled. A spring 48 having its ends engaging in the seats A43 and 47 is adapted. to normally hold, the lower end of the lever 41 in forward position.

Mounted on or secured to one end of the pivot pin 46 is an arm 49 having a contact fr member 51 pivotally mounted on its outer end. The position of the contact member 51 may be adjusted by means of a set screw l52 as clearly'shown in Figs. 6 and 11 of the drawings. A stopY 53 is mounted on any con- 1; angular. slot 37, kthe rear portion of the slot y Y being substantially horizontal Vfor receiving venient portion o-f the car forengaging the contact member 51 when Vthe slack in the brake operating mechanism exceeds a predetermined maximum,during the operation of the brake. This stop is so mounted that whenr s..

the brake operating mechanism is properly adjusted it will not be operated by the stop 53, when the brakes are applied.

As the brakeshoes wear or as the slack accumulates in the brake operating mechanism, the levers 18 and 19 will tend to move beyond their normal position in applying the' brakes, and this in turn will cause the contact member *51. to engage the stop and move the lever 41 forwardly, thereby compressing the i spring 48. Y

The detent 42'which is carried by the lever 41 will tend to ride forwardly over the teeth, and when the vslack is such that the forward movement of the housing 24 is equivalentV to the distance between` two of the notches, the detent will ride over the adjacent tooth, and when the brakes are released the spring 48 will expand and move the housing 24 forwardly, causing the teeth33 to ride forward-V lyone notch over the teeth 35 of the holding member 34. The partsA are so constructed that the ldetent 42 will be advanced one or more teeth for each reciprocation of the arm 49 for taking up slack in excess of the predetermined maximum. n

In applying new brake shoes it is necessary to adjust the holding mechanism to provide sufficient clearance for the new'shoes, and in f.,

will take up the slack and at the same time "t will n-ot'interfere with thevnormal application of the brakes.

VIn the present construction, when the brakes are applied withexcessive slack in the brake operating mechanism the lever arm 39 and contact arm 51 will rotate to a posit-ion to pass beneath the contact membertopermit sutlcient movement ot the lever 13 to apply the brakes, and wien the brakes are released the contact arm will move about its pivot and permit'the lever to return to its normal inoperative position. y

This operation will take up a portion of the slack and the succeeding applications ot the brakes will take up the additional slack in the mechanism. This is considered an important feature ot the invention since the workman who changes the brake shoes need not be particular about the amount or' slack he provides so long as sutncient slack is provided'to apply the shoes.

Suitable means are provided for preventing accidental disengagement of the teeth 33 and 35, when the adjusting mechanism is not being operated. Any suitable mechanism may be provided for this purpose. As shown, the forward portion of the retaining member 34 is provided with a pivoted dog 54 which in normal position is adapted to engage the ledge 28, see Fig.` 7, for preventing the housing 24 from rising relative to the holding member 34 whereby vthe teeth 33 and'35 will be maintained in engagement. Any appropriate means may be provided for moving the dog 54`to inoperative position to permit the housing 24 toadvance relative to the holding member 34.

In the form of construction shown, `the dog 54 is provided with a rearwardly extending arm or linger which is adapted to be engaged by a linger 56 for rotating the dog 54 to the position shown in Fig. 8 when the lever 4l is operated, thereby permitting the teeth 33 on the housing 25 to ride over the teeth 35 on the retaining member 34. Wlhen the brake is released, thelever 4l will be returned te normal position by the spring 48, permitting the dog 54 tofall by gravity into position above the ledge 2S.

The operationot the device may be briefly summarized as follows lVhen thegbrakes are applied in the usual'manner, the ends .of the levers to which the slackadjuster 23 is 'attached will be moved towardV the stop members 53, see Figs. l, 2 and 3, and the Contact member 5l will be so adjustedby the seU screw 52 that it will engage orbe closely adjacent to the stop when the brakes are applied before slack develops in the operating mechanism.

As the shoes wear, causing a gradually increasing slack in the operating mechanism, the levers 18 and 19 will move farther and farther toward the'stops 53, thereby causing the arms 49 to rotate the levers 41 more and more against the compression of the springs 53 on the lever 41 will engage the member 55 and turn the dog 54 out of engagement with 'the ledge 23'wh'ereupon wheny the brake is l again released the spring 48 will return the lever 4l tonormal position and advance the housing 24 to takeupfthe slack to compensate for the 'wear yoiE the brake shoes and'other parts of the mechanism'.v i The release ot the lever V4lwill release the dog 54 which in turn will Jfallby gravity against the edge of the ledge 28-and when the housing is lowered after its teeth 33 ride over the teeth on the holding member 34 it will Vtally in position above the ledge l28 for preventing 1accidental disengagement of the teeth 33'and35. e l

Vhile` two of the slack'adjusters 23 are employed and. are shown as being attached to the cylinder levers, one to the fulcrum end of one lever andthe other to theend opposite the `fulcrum of another lever, it' is understood that only one need be', employed and `that'it may be used on any suitable movingportion of the brake operating mechanism.

The attaching member 24 vis preferably in the form of a housing in order to protectthe operating Amechanism, but it is `understood that it maybe-otherwise.

When it is desired to ad member relative to the holding memberv for providing excess slack for any reason as for applying new'brake shoes, the dog 54 is dise engaged in any suitable manner' as by the linger and the attaching member 24 'elevated todisengage its teeth lfrom the teeth 35 andthen moved along the holding member unt-il the desired slack is provided. l

lt lthought from the foregoing, taken in connection with the accompanying drawings, that the construction and opera-tion of my device will be apparent to those skilled in the art, and that ,various changes in size,2shape, proportion Vand details of constructionj may be made without departing from the'spirit and scope ofthe appended claims;l .Y

`I claim as my invention; i

l. In .brakev pei-ating mechanism including a brake rod anda leverr tor operating saine, slackadjusting device con-V nected-tosaid rodand lever and movable therewith,saiddevice comprising a housing7 a. rack associated therewith, a holding member cooperating withsaid rack,` adjusting mechanism comprisinga stop and a pivoted arin'for engaging said stop Vfor movement of said adjusting mechanism and for operating the sameto advance said rack relative to 4said holding member during the operation of said brake operating mechanism' for taking up the slack therein, said arm be- 'ing adapted to pass-.by said stop when the effectingthe just the vattaching .mechanlsnn j, teeth longitudinally thereof, a holding mem-k engaging said lirst-V contact member on said arm for stop for oscillating said arm.

0. In a slack adjuster for brake'operating an attaching member having engaging sale having teeth for named teeth, adjusting mechanism comprising a spring-pressed arm, a spring-pressed paWl for engaging the teeth on said attaching member, said paWl being adapted to be moved along said attaching member by said arm for advancing the attaching member one stepV for each oscillation of said arm when the slack in said bra-ke operating mechanism exceeds a predetermined maximum and movable means on said arm for engaging a stop for oscillating said arm.

11. In a slack adjuster for brake operating mechanism, an attaching member having a rack extending longitudinally thereof, a holding member having teeth cooperating with the teeth of said attaching member for holding the parts in adjusted position, an arm, a spring engaging said arm, a pawl movable With said arm, a stop, a contact member mcvably mounted on said arm and adapted to engage said stop for moving said arm for storing energy in said spring and for advancing said paWl along said rack during the application of' the brakes When the slack in the brake operating mechanism exceeds a predetermined amount, said contact member being movable past said stop in both directions.

12. In a slack adjuster for brake operating mechanism, an attaching member adapted to' be connected to a brake rod, a holding member adjustable along said -attaching member and adapted to be connected to a brake lever, interengaging teethxed to said members, means for advancing said attaching member one er more steps during the application and release ofsaid mechanism when the slack in said mechanism exceeds a predeterminec amount, and means be applied irrespective of the amount of slack in said mechanism'.

13. In a slack adjuster for brake operating mechanism, an attaching' member adapted to be cennected to a brake rod, a holding member adjustable through said attaching member and adapted to be connected to a brake lever, interengaging teeth xed to said members, means for advancing said attaching member one or more steps during the application and release of said mechanism When the slack in said mechanism exceeds a predetermined amount, and means for preventing the disengagement of said teeth except when said first-named means is operated. Y

14. In combinatiombrake operating mechanism comprising a system of movable levers and brake rods for operating the brakes, slack adjusting means associated with said system for taking up excessive slack therein, said whereby said brakes mayV means comprising a stop,

detent;

and rods for'operating the brakes, a slack adjusting device associated with a movable membery of said system for taking upV excess slack in said system, said device comprising holding and adjusting' means, a stop land means for engaging said stop forl advancing said means along said movable member for taking up the slack in said system When the same exceeds a predetermined maximum and for lmoving past said stop When the slack exceeds a predetermined amount, said last named means being movable past said stop in a reverse direction Without affecting the adjustment of said first named means.

16. A slack adjuster for use on brake operating mechanism, comprising holding meansA adapted to be connected to a movable portion of said mechanism, attaching means adapted to be connected to another portion of said mechanism and adjustable along said holding means for taking up slack in said mechanism and adjusting mechanism adapted to automatically adjust one of said means relative to the other during the application and release of the brakes When the slack in said brake operating mechanism exceeds a p determined amount, said mechanism comprising a movable rmember adapted to engage a relatively fixed member for operating said adjusting mechanism When moved in one direction and adapted to be moved past said A opposite direction Without affecting said mechanism.

17. In combination, brake operating mechanism comprising a system of movable levers and brake rods for operating the brakes of a vehicle, a relatively iixed member, a slack adjusting device interposed in said mechanism for taking up the slack therein and comprising a movable member for engaging said relatively fixed member for operating said device during the operation of the brakes when the slack in said mechanism exceeds a predetermember being past said fixed member in a reverse direction Without operating said device.

18. In brake mechanism of the class described, the combination therewith of a slack adjuster adapted to connect tWo adjacent a rack, a detent for engaging said rack and means for en"-` ga'gingsaid stop for advancing saiddetent along the teeth of saidrack-When the slack 1n a reverse direction Without affecting said 5. In combination, brake operating mech-j, anism comprising a system of'movable `levers moving parts of theV mechanism, said adjuster Y holding members against relative movement 1n one dlrectlon, an actuating mechanism 1n-v cludmg a contact member adapted to` advance a detent along the ratchet teeth when excessV brake travel exists7 and spring. vmeans forl moving the holding `member relative to the attaching member upon release of the brakes' after the detent has been advanced along the teeth, and a dog adapted to positively lock theattaehing andholding members 1n adjustment when the brakes are in normal release nostion.

Intestmony whereof I alX my signature.

PERCY B. CAMP. 

